Calendar issue (not Calendar Error)

I'm sure that this isn't to much of an issue for some but I'm having this issue, and wasn't able to find an answer anywhere. This isn't the Calendar Error problem

So I have a MV-4F with a Unibios 4.0. The battery is a Ni-Cd rechargeable, and all the setting stay, and I run it almost daily myself and find my kids on it all the time.

The clock runs fine, and as long as it stays on it will stay 100% in sync with the wall clock that I have near by. When I turn it off, it looses time, like ~45 every hour, it doesn't stop or reset.

Does anyone know what could be causing this?

Reads like the battery is being recharged by the mobo when it's on and when you turn it off,the battery is not holding enough of that charge to keep accurate time.
If the battery is old,replace it.
BB

Agreed Big Bear.

Thanks for the suggestion, it is an original battery that I grabbed from a parts board. I ordered a new battery. I'll report back when I put it in.